This invention relates to a system for fastening together two articles, such as staircase rails, in a mating relationship.
Typically, staircase rails are fastened together in an end-to-end relationship by forming a first opening or bore in the bottom of one of the rails near one end thereof, and forming a second bore which extends from the first bore to the end of the rail. The side of the first-mentioned bore nearest the rail end is morticed to accommodate a flat washer and nut. A hanger bolt with a standard washer is then used to join the two rails together by screwing the bolt into the end of the other complementary staircase rail so that machine screw threads of the bolt will extend through the second bore into the first bore. The washer and nut would then be placed on the bolt and tightened to pull the one staircase rail against the other staircase rail in a secure end-to-end disposition.
This arrangement, although tightly securing two staircase rails together, is difficult to manipulate--both to form the mortice and to tighten the nut against the morticed part of the first bore.
Other approaches are also used for joining two staircase rails together, but such approaches generally do not tightly secure the two rails together. For example, rails may be placed in an end-to-end relationship and then a wood screw screwed from the underneath side of one rail at an angle upwardly and toward the other rail to generally pull the two rails together. Alternatively, the two rails could simply be secured together by use of dowels extending parallel with the rails, and an adhesive such as epoxy. Neither of these techniques, however, sufficiently secures the rails together to hold up under the use and abuse staircase rails typically receive.